[TYPO3] All installed extensions work, but some do not show in ext. manager

[Hans van Dijk]

Hi List,

I use T3 4.0 and PHP 5.
What's bothering me for the last few days, is that when I install a  
new extension, ALL new extensions work, but SOME do not show up in  
the "loaded extensions"??

I searched the list for an answer, but nobody seems to have the same  
problem as I do!

When I look in the localconf.php, they all are in the  
"$TYPO3_CONF_VARS['EXT']['extList']" - array and they work.
Some of them (for example:  
'tt_products','mbi_products_categories','kickstarter','sr_static_info' ) 
  just don't show up, and therefore can not be configured using the  
extension manager.

I've installed them local and global, but eitherway no success.
Is there anybody having any idea what could be wrong?

Thank you for pointing me in the right direction...

Regards, Hans